That's what I thought, then I encountered the same problem on Safari too (Chrome was the initial problem).

Then another problem, from my control panel I tried to click this link, and it loaded the page with the proper URL, but it was still my user CP, not the appropriate page. Same problem in Safari again. And freshly cleared cache again.

So either something super silly is going on with my entire computer, or your server might be hiccuping.

Hah, that's pretty nifty.
I also realized what the problem is, not sure why it's a problem though.

pbnation.com/usercp.php/anything-here will take the user to the CP under all circumstances (I think?)

For some reason from the CP, no matter where I went, instead of showthread.php it kept the usercp.php and tacked on the rest of the file name to that. Any idea why that might happen on multiple browsers with a cleared cache? And I swear, I try to participate only in safe-surfing!

That appears to be true for any page on the site. It has something to do with the mod_rewrite rules the server is running. I'll see if there's anything I can do about it in the morning, but I'd suggest making a habit of only using valid urls.

That appears to be true for any page on the site. It has something to do with the mod_rewrite rules the server is running. I'll see if there's anything I can do about it in the morning, but I'd suggest making a habit of only using valid urls.

The only time I can see it making a difference would be coming from the CP though because that will constantly bring the user back to the CP without knowing what the problem is. With a showthread= you will at least know that your initial URL was not valid, or just not what you wanted.

Maybe something as simple as if the system detects something after .com/usercp.php, the user will not necessarily be re-directed, but just get a popup recommending he clear his cache and close the PbNation window or tab. After clearing my cache nothing changed, but closing the PbNation tab and trying again fixed the problem.